Elevator for silos



Dec. 6, 1955 FERRls 2,725,957

ELEVA'I OR FOR SILOS Filed April 15, 1953 2 Sheets-Sheet 1 Dec. 6, 1955 Filed April 15, 1953 R- G. F ERRIS ELEVATOR FOR SILOS 2 Sheets-Sheet 2 Jfz'y 2.

United States Patent ELEVATOR. FOR SILOS" Robert'G. Ferris, Harvard,,lll., a ssignor to Starline, Inc., a' corp oration of" Illinois Application April'15,;1953, Serial'No;'348,866 Claims. (Cl; 187 -6).

This invention relates to an elevator for silos, and in particular it relates to an elevator construction which may be mounted in the vertical silage drop chute of a silo so that a person may ride in the' elevator to any desiredlevel of the silo when it is necessary to remove silage for feeding.

The usual silo constructionlhas avertical silage drop chute at one side of the silo which is usually within or in communication with the barn, and a vertical series of removable doors in the silo wall inside the drop chute so that when it is necessary to take silage. out of the silo for feed a person may go up the silo wall on a ladder and enter an open door at the top of the silage in the silo. Enough silage for a days feeding may then beforked out the open door to drop to the floor at the bottom of the drop chute.

Since the silage drop chute communicates with the inside of the barn the moist air from the barn escapes through the drop chute, and in cold weather the ladder which must be usedto ascend the-silo wall becomes frosty and very hazardous to climb. Many farmers keep a hired man all winter simply because of the hazardous job of climbing the silo every day.

This invention. consists of a simple elevator mechanism of the counterbalanced, dumb-waiter type which may be mounted in the vertical drop chute of a silo so that a person may get into a small one-man elevator car to ride to the level of silage in the silo, and may likewise use the elevator for descendingafter he has forked out the necessary amount of silage. Both the ascent-and descent may be accomplished without the. necessity of applying either. mechanical or human. power to the elevator mechanism to overcome the weight of the counterbalance.

The invention. is. illustrated in a. preferred embodiment in the accompanying drawings. in which:

Fig. 1 is a side elevational view of a silo, partially in section, to show thev elevator. structure mounted in the silage drop chute;

Fig. 2 is a sectional view on an enlarged scale showing the. brake mechanism for. the. elevator;

Fig. 3 isasection through the elevator car; and

Fig. 4 is a top planview oftheelevator car.

Referring tov thedrawings. in greater. detail, and referringfirst to. Fig. l, a silo.'9. is. providedwith a wall 10, a roof-11, a. rectangular silage. drop chute 12 and a vertical series of spaced openings 13 in the silo wall within the drop chute which are provided with removable doors 14. Thus, as silage is. removed from the top of the silo the appropriate door in the wall may be removed to permit silage'to be tossed'out of'the silo through the door, and when thelevel of the silage is down far enough to use the next lower door in the series, the upper door may be replaced in the opening and the next lower door removed.

Mounted on the top of the drop chute 12-and the top of the silo wall is 'a frame 15 for the elevator structure which has its outer end extending a short distance 2? beyondthe wall of'the drop chute. Mounted above the center of the drop chute is an elevator sheave, indicated generally at 16, and at the end of the frame I'S'outsid" the walloffth'e drop chute is a-seco'n'dshe'ave 17. As best seen in Fig. 2 the sheaves are of the convoluted, or sprockettype whichis suitable for use with roller chain, and a roller chain. 18 is trained over the sheaves-so that one end is inside the drop chute 12 and the other end hangs outside the drop chute below the end of the frame 15.

Referringagain.to' Fig. 1, a one-man elevator car, indicated generally at 19, is suspended from the roller chain ISinside the drop chute while a hollow'counterweight member 20 is suspended from the opposite end of the chain 18' outside the-drop chute 121 As bestseen in Fig. 2, the elevator sheave'16 consists of a sprocket portion 21 and an integral grooved brake wheel 22. A brake yoke 23 is hung from the frame 15 below the sheave 16 to receive a. brake lever 24which is pivoted'v on a pin: 25' in the yoke 23, and a brake cable 26 which is trained around the grooved brake wheel'22 has both ends secured! to the brake lever 24- so that the tension of the brake cable 2 6" on the grooved wheel 22 is determined by the position of the brake lever 24. At the freeend of the brake lever, adjacent the silo wall, is a spring yoke 27 to receive a brake pulley 28 which is journalledin the yokeandin the'end of the brake lever 24; and a tension sp'ring29 isstret'ched between the frame 15' and the spring yoke 27 so as. to normally urge the brake lever 24 to a position in which the brake cable 2'6 is. drawn tightly ontothe grooved wheel 22 to prevent rotation of the wheel and the integral sprocket 21'.

As seen in-Figl' the elevator car 19 has a supporting yoke 30' which is. formedfrom' a channel member and which extends downwardly to provide frame pieces for a sheet metal side wall 31. for the elevator car. Because of the small' size of the normal silage drop chute the elevator car 19ordinaril'y is only large enough to accommodate one person. Mounted on the supporting yoke 30 is a pivoted brake release arm 32 which has an eye 33 to receivea brake releasecord 34 which'is trained over the brake pulley 28 and over a second pulley 35 which is securedto. the bottom of the silo wall. The length of the brake a'ctuating'cord 34 is such thatpivotal movement of the brakerelease arm 32 will draw the cord 34 sidewise a sufiicientidistance to pull the brake lever 24 down against the tension of the spring 29 so as to loosen the brake cable 26 on the grooved wheel 22 and permit the-sheave 16 to rotate in the direction whichmay be determined by the relative weights of the elevator car 19and the counterweight 20.

As best seen in Fig. 3} the elevator car 19 has a bottom 3'6Which is providedwith a transverse central channel member 36a to receive a pin 37 by means of which the bottom 36 is hinged to the lower end of one arm of the yoke 30. The channelmember 36a is pro: videdwith an apertured bracket'38 to receive a latch bolt 39 having a latch stop 40. A compression spring 41 is coiled around the latch bolt39 between the latch stop 40 and'the bracket 38 so as to normally urge'the latch bolt into engagement with an aperture inthe lower end oflthe other arm of the supporting yoke At tached to thereari of the bolt-39 is a trip wire 42 which extends along the channel 36a ofthe elevator car, around the hinge pin 37 and upwardly along the first arm of the yoke 30 to a trip finger 43 which is mounted in a slot 44 in one side of the channel which. forms the yoke 30. Thus, in order to open the bottom 36' of the elevator car it ismerely necessary to" pull the trip finger 43' upwardly in the 'slot 44 to unlatchthe bracket 38, permitting the bottom" 36 of the elevator car to swing into the-open-po'sitio'n shown in broken' lines in Patented Dec. 6, 1955.

Fig. 3. A pull cord 45 is secured to a point 46 on the bottom 36 of the elevator car to permit the bottom to be drawn to its closed position by a person standing within the elevator car on the foot rests 47 which are positioned on opposite sides of the car just above the 6 bottom 36.

The elevator is used as follows: The counterweight 20 is filled with sand, bricks or other material until it is sufiiciently heavy to overbalance the weight of the elevator car 19 and the individual who uses the elevator 10 car. Thus, the counterweight should be adjusted to the weight of a person who will normally use the elevator, and should weigh some 20-50 pounds more than the car and the man. The bottom of the silo drop chute 12 is far enough above the floor of the silo and the 15 barn to permit a person to climb into the elevator car 19 when it is on the ground. After getting into the elevator car the person who is using it pivots the brake release arm 32 to loosen the brake cable 26, whereupon the counterweight 20, overbalancing the weight of the 20 elevator car 19 and its occupant, causes the car to move upward in the silo drop chute. When the elevator is at the appropriate position for the occupant to climb into the silo through the open door at the top of the silage the occupant releases the arm 32 so that the brake cable 26 may grip the wheel 22 to stop the car. He then pulls the trip finger 43 for the bottom 36 of the elevator car so that the bottom swings to its open position, whereupon he may shovel as much silage as is necessary out of the opening 13 so that it drops to 30 the bottom of the drop chute 12, falling through the open bottom of the elevator car. When the necessary amount of silage has been shoveled out, the bottom 36 of the elevator is pulled shut by means of the cord 45, and the person then shovels 40 or 50 pounds of silage into the bottom of the elevator car before getting into the car himself. The weight of the silage shoveled into the car is great enough to overbalance the counterweight 20 so that when the brake is released the elevator car descends the chute 12. The foot rests 47 are provided so that it is not necessary for the occupant of the car to stand on the bottom of the car; so that accidental unlatching of the bottom of the car presents no danger to the occupant. When the elevator car reaches a position a short distance above the pile of silage on the barn floor, the occupant of the car may trip the car bottom to dump the silage which is in the car.

Frequently the amount of silage shoveled out of the silo into the drop chute is so great that the pile of 50 silage beneath the chute prevents the elevator car from descending far enough for the occupant to get out of the chute over the side of the car. Under these conditions he may simply slide out the bottom of the car into the top of the silage pile and down the pile of silage beneath the lower end of the drop chute.

Ordinarily the elevator car is so mounted in the drop chute that the hinged bottom 36 swings away from the wall 10 of the silo. This is so that a person may reenter the car through the bottom when it is several feet 30 off the ground by climbing up the ladder on the silo wall and into the car.

In some silos the drop chute is either round or semicircular, so that the bottom of the elevator car can only be opened a short distance when the car is in an elevated position with its bottom actually inside the confines of the drop chute. With this type of silo the elevator is most conveniently used by leaving two of the doors 14 out of the openings 13 in the silo wall, running the elevator car up enough to get out of it and into the silo through the upper of the two openings from which the doors are removed and then forking the silage out through the lower opening underneath the car without having to open the car bottom.

The foregoing detailed description is given for clearness of understanding only and no unnecessary limitations are to be understood therefrom, as some modifications will be obvious to those skilled in the art.

I claim:

1. In a silo having a vertical silage drop chute, elevator mechanism comprising: a frame surmounting the drop chute; sheave means journalled on the frame; a flexible member trained over said sheave means; a one-man elevator car secured to one end of said flexible member inside the drop chute, said elevator car having a hinged bottom; releasable means for securing said hinged bottom in a closed position, said means being releasable by a person standing upright in the elevator car to permit the bottom of the car to swing downwardly on its hinge; foot rest means for a person in the car to stand on when said bottom is open; a counterweight secured to the other end of the flexible member, said counterweight being constructed to receive and retain material by means of which its weight may be adjusted so as to overbalance the weight of the car and an occupant; brake means on the frame to engage said sheave means; and means in the elevator car for controlling said brake means.

2. In a silo having a vertical silage drop chute, elevator mechanism comprising: a frame surmounting the drop chute; a first sheave journalled on the frame above the drop chute; a second sheave journalled on the frame outside the drop chute; a flexible member trained over said sheave; a one-man elevator car secured to the end of said flexible member inside the drop chute; a counter weight secured to the end of the flexible member outside the drop chute, said counterweight being constructed to receive and retain material by means of which its weight may be adjusted to overbalance the weight of the elevator car and an occupant; a brake wheel coaxial with and rotatable with said first sheave; a brake arm pivoted beneath said brake wheel and having a pulley at its free end; a brake spring connecting the free end of the brake arm to the frame; a friction band trained over said brake wheel and having its ends secured to said brake arm so that said band is normally drawn into close frictional engagement with the brake wheel by the brake spring; an endless cord extending over the pulley on the brake arm and over a second pulley adjacent the base of the silo; and a brake release crank pivoted on the elevator car and engaging said endless cord so that pivoting of the brake release crank will tension said cord to stretch the brake spring and release the frictional engagement of the friction band on the brake wheel.

3. In a silo having a vertical silage drop chute, elevator mechanism comprising: a frame surmounting the drop chute; sheave means journalled on the frame; a flexible member trained over said sheave means; a oneman elevator car secured to one end of said flexible member inside the drop chute; a counterweight secured to the other end of the flexible member, said counterweight being of such mass as to overbalance the weight of the elevator car and a person in the car to permit the person to ride by gravity power to an elevated position in the drop chute and drop a substantial mass of silage from the silo to the bottom of the drop chute; a hinged bottom on the car to permit the person to place sufficient silage in the car when it is in said elevated position with the bottom closed that the weight of the silage added to the weight of the person and of the car may overbalance the mass of the counterweight and permit the person to return by gravity power to a position near the bottom of the drop chute; releasable means for securing said hinged bottom in a closed position, said means being releasable by a person standing upright in the elevator car to permit the bottom of the car to swing downwardly on its hinge to dump said silage; foot rest means for a person in the car to stand on when said bottom is open; brake means on the frame to engage said sheave means; and means in the elevator car for controlling said brake means.

4. In a silo having a series of vertically spaced openings provided with movable doors, and a vertical, enclosed silage drop chute spanning said doors, elevator mechanism comprising: a frame surmounting the drop chute; sheave means journalled on the frame generally in a plane through the center of the drop chute; a flexible member trained over said sheave means; a one-man elevator car secured to one end of said flexible member inside the drop chute, said elevator car having closed upright sides and a horizontal bottom forming a container, said bottom being hinged to swing downwardly to an open position; latch means controllable by a person standing upright in the elevator car to releasably secure said bottom in a horizontal position; counterbalance means on the other end of said flexible member, and brake means for controlling the movement of said elevator car from inside the car.

5. In a silo having a vertical silage drop chute, elevator mechanism comprising: a frame surmounting the drop chute; sheave means journalled on the frame; a flexible member trained over said sheave means; a oneman elevator car secured to one end of said flexible member inside the drop chute, said elevator car having,

bottom means which is movable between a closed position and an open position; means for a person in the car to stand on when said bottom is open; means operable by a person standing upright in the elevator car to control the position of said bottom; means on the other end of the flexible member positioned and arranged to receive varying masses to overbalance the weight of the elevator car and an occupant; and brake means for controlling the movement of said elevator car from inside the car.

References Cited in the file of this patent UNITED STATES PATENTS 

